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© T. G. Gopakumar, IITK |
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Molecular Functional Materials Research Group |
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A molecule with aromatic (semiconducting due to low HOMO-LUMO gap) part and aliphatic chains (wide HOMO-LUMO gap) of different length (dL, dR) on both sides or aromatic part is kept in between two electrodes (gold). This creates an asymmetric double barrier junction (corresponding energy diagrams is shown).
When no potential is applied between left and right electrode no electrons are transported. The rate of electron tunneling through different barriers are different due to the length of aliphatic chains. Therefore the transport of electron at different bias polarity differs drastically. This leads to an asymmetric current voltage curve characteristics.
B. Larade et. al Phys. Rev. B, 2003, 68, 235305 |
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Molecular Diode |